Targeting trachoma control through risk mapping: The example of southern Sudan

Authors: Archie C. A. Clements, Lucia W. Kur, Gideon Gatpan, Jeremiah M. Ngondi, Paul M. Emerson, Mounir Lado, Anthony Sabasio, Jan H. Kolaczinski

This study sought to develop maps to help target the available resources for trachoma surveys and interventions in southern Sudan to areas where they are most needed, thereby improving programme efficiency.

Trachoma, caused by the bacterium Chlamydia trachomatis, is the leading cause of preventable blindness worldwide and a major cause of blindness in southern Sudan. However, the trachoma distribution in southern Sudan has only been partially established and many communities in need of intervention have not been identified or targeted. Incomplete mapping and intervention coverage is largely attributable to trachoma resources being scarce and not always deployed most efficiently. This study aimed at improving programme efficiency by developing maps to help target the available resources for trachoma surveys and interventions to areas where these are most needed. Data on active trachoma prevalence, collected during baseline surveys between 2001 and 2009, were incorporated into Bayesian geostatistical models to develop a national trachoma risk map. The model predicted the west of the country to be largely at no or very low trachoma risk, while most of the high-risk areas are located in the centre, north, and southeast. Risk mapping has allowed southern Sudan’s trachoma control programme to identify areas where collection of additional data would be most useful. As a direct result, baseline data were collected in March 2010 for the whole of Unity state, with antibiotic mass drug administration being scaled up from June 2010 onwards.

Citation: Clements ACA, Kur LW, Gatpan G, Ngondi JM, Emerson PM, et al. (2010) Targeting Trachoma Control through Risk Mapping: The Example of Southern Sudan. PLoS Negl Trop Dis 4(8): e799. doi:10.1371/journal.pntd.0000799